IP communication involves the transmission of messages in the form of one or more data packets. The data packets include a source address and at least one destination address. A switch is a network device that directs traffic towards the destination address. Switches include multiple inputs and multiple outputs. A crossbar switch includes a selectable connection from each of the multiple inputs to each of the multiple outputs. A crossbar switch permits only one data packet to be transmitted to any one output at any particular time.
Arbitration schemes regulate data flows. In one example, the input must request to send data and receive a confirmation that data may be sent. These communications in the switch require time, which increases packet latency. In addition, congestion may occur at the inputs, at the outputs, or at the crossbar.